Link Aggregation problem

Hi,

I have a hp 5820 comware and 3com 4200g switches, I am trying to configure dynamic link aggregation, I enabled LACP on the two uplinks on 4200g and created the required link aggregation group on 5820 and set it to dynamic.

When I add the uplinks on 5820 side, communication with 4200G stops and no ping to switch, If I add one interface it works but when I add the second interface the problem happens.